Generally, semiconductor devices such as transistors may be formed in semiconductor materials from column IV of the periodic table such as silicon, germanium, etc., that have been doped with various dopants such as p-type dopants and n-type dopants. These semiconductor materials may have an energy gap between a valence band and a conduction band known as a band gap that is larger than a conductor (in which the valence band and conduction band may overlap) and smaller than an insulator (in which the valence band and conduction band are so far apart as to effectively prevent electrical conduction). These semiconductor materials, along with the different types of dopants, may be utilized along with a gate dielectric and a gate electrode to define a channel region wherein the flow of current can be controlled by the selective application of voltage to the gate electrode.
Recently, there has been much research into using materials other than the semiconductor materials from column IV of the periodic table. Materials that are being researched include a combination of elements from both column III and column V of the periodic table, known as III-V materials. These III-V materials may have a band gap that allows for their usage as semiconductor materials.
However, while the III-V materials may be used as a substitute for the semiconductor materials from column IV, the materials themselves leave much to be desired when it comes to using these materials in the mass production of devices for usage by consumers. As merely one example, the conduction band and valence band energies of many of the III-V materials, while still functional, may be ill-suited for actual usage. Additionally, the trap density at the interface between many of the III-V materials and the gate dielectric may be exceedingly high as compared to materials from column IV of the periodic table.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.